def near_by_road(lat,lon):
    import math
    lat_list=[]
    lon_list=[]
    osm_id=[]
    comp=1000
    for line in open("road.b","r"):
        para=line.split(";")
        lat_list.append(para[1])
        lon_list.append(para[2])
        osm_id.append(para[0])
    for i in range(len(osm_id)):
        lat2,lon2=float(lat_list[i]),float(lon_list[i])
        lat1,lon1=lat,lon
        dlat = lat2 - lat1
        dlon = lon2 - lon1
        dist2 = dlat * dlat + dlon * dlon
        dist=math.sqrt(dist2)*100
        if dist<comp:
               comp=dist
               x,y,z= osm_id[i],lat_list[i],lon_list[i]
    return x
